The race to succeed Rhodri Morgan as Welsh Labour leader began today after the first minister confirmed he was standing down.

Morgan said he wanted to make way for a new leader before he was pushed out of the job he still loved after a decade at the helm.

An overthrow "frequently happens if you stay more than 10 years," he told reporters yesterday at a special meeting of Labour chiefs and assembly members in Cardiff.

"I have seen it happen to leaders – Margaret Thatcher, Tony Blair and so forth – I don't want that to happen to me."

The Welsh Labour executive yesterday approved the timetable and procedure for an eight-week leadership election that officially starts at midday today. Setting out his desire for a smooth handover, Morgan said he would remain in charge until the Welsh government's budget was signed off in early December.

Morgan, who is 70, said he planned to stay on as an assembly member and focus on his constituency of Cardiff West until the 2011 elections to avoid triggering a byelection.

His retirement plans include writing a book on the first 10 years of devolution, which Morgan said had given Wales "confidence in its own abilities to run its own affairs".

Morgan defended his legacy when he was challenged about eye-catching policies such as free prescriptions, free hospital parking and free bus passes.

In an interview on BBC Radio Wales's Good Morning Wales, he said: "It's right that stabilising the ship at the beginning of when I took over was very important. We had unbelievably difficult birth pangs for devolution from the various incidents that took place regarding some of our leading politicians, the wafer-thin majority in the referendum back in September 1997.

"When we started introducing policies which were different from in England, there is a kind of colonial-era psychology which says if you're doing something different from England it must be a gimmick."

He pointed out that England was now copying Wales in scrapping parking fees outside NHS hospitals.

His last two months in office would be taken up with dragging the economy out of the recession, combating swine flu and finalising the government's spending plans for next year.

Would-be leaders need six nominations from assembly members to get on the ballot paper.

Like the outgoing first minister, Jones, the bookmakers' favourite, is a rugby fan and fluent Welsh speaker.

Lewis's battle cry to "let Labour be Labour" will strike a chord with the grassroots, while Hart has strong backing among trade unions and the support of Andrew Davies, the finance minister, an influential ally.

With an SNP administration running Scotland, the new first minister could next year become the most senior Labour politician in a governing role if the Conservatives win the general election.

Morgan's successor will also have to see out the remaining year-and-a-half of the One Wales coalition with Plaid Cymru in the Welsh assembly.

Morgan vowed to keep out of the contest and refused to anoint a candidate.

He told ITV Wales: "It's up to them to make their case to the Labour electorate but I won't be endorsing them."

Gordon Brown led tributes from across the political spectrum for the man who dominated the first 10 years of devolution.

The prime minister said: "His achievement is historic. For a decade, he has led Wales with boundless energy and commitment – improving the public services, economy and prospects of people across Wales."

Ieuan Wyn Jones, the Plaid Cymru leader and deputy first minister, said: "We all owe a debt of gratitude to Rhodri Morgan for the deft way in which he steered the devolution project following the problems caused by the resignation of Alun Michael."